Analytical method and apparatus

ABSTRACT

An improvement in a method for analyzing labile-hydrogencontaining compounds present in mixtures wherein the mixture is passed over a labile-tritium-containing substrate to effect exchange of the labile hydrogen with the labile tritium and the resulting tritium-containing compound is detected and measured, the radioactivity measurement being used to determine the amount of the labile-hydrogen-containing compound in the mixture, which comprises passing the effluent from the detecting means through a high capacity &#39;&#39;&#39;&#39;tritium trap&#39;&#39;&#39;&#39; containing a substance having labile-hydrogen atoms to prevent the venting of dangerous amounts of radioactive tritium-containing compounds into the atmosphere. The invention also provides the combination of a suitable &#39;&#39;&#39;&#39;tritium trap&#39;&#39;&#39;&#39; with an analytical system for carrying out the above method comprised of a column connected to the outlet of the detecting means and which contains a substance having labilehydrogen atoms.

United States Patent [151 3,660,036 Benson 1 May 2, 1972 [54] ANALYTICALMETHOD AND APPARATUS Primary Examiner-Morris O. Wolk AssistantExaminer-El1iott A. Katz [72] Inventor: W Bensonr'rexas Y AttorneyM. N.Cheairs, Elizabeth F. Sporar and Neal E. [73] Assignee: MonsantoCompany, St. Louis, Mo. wllhs [22] Filed: Dec. 22, I969 [57] ABSTRACT[21] Appl. No.: 886,953

[52] 0.8. CI ..23/230 R, 23/232 R, 23/253 R, 23/254 R, 250/106 R, 23/232C, 250/106 T [51] Int. Cl ..G01n 23/12, G21h 5/00 [58} Field of Search..23/230, 232, 253, 254; 176/10, 176/19, 19 L; 252/301.l; 73/231;250/43.5,44, 106 T [56} References Cited UNITED STATES PATENTS 3,560,1582/1971 Benson ..23/230 R OTHER PUBLICATIONS An improvement in a methodfor analyzing labile-hydrogencontaining compounds present in mixtureswherein the mixture is passed overa labile-tritium-containing substrateto effect exchange of the labile hydrogen with the labile tritium andthe resulting tritium-containing compound is detected and i measured,the radioactivity measurement being used to determine the amount of thelabile-hydrogen-containing compound in the mixture, which comprisespassing the effluent from the detecting means through a high capacitytritium trap containing a substance having labile-hydrogen atoms toprevent the venting of dangerous amounts of radioactivetritium-containing compounds into the atmosphere. The invention alsoprovides the combination of a suitable tritium trap with an analyticalsystem for carrying out the above method comprised of a column connectedto the outlet of the detecting means and which contains a substancehaving labile-hydrogen t Benson, Analytical Chemistry, Vol. 38 pp. 1353-1356 (Sept. 3 mm 1966) 19 Claims, 3 Drawing Figures ANALYTICAL METHODAND APPARATUS BACKGROUND OF THE INVENTION The present invention relatesto an analytical method and apparatus. More particularly, the presentinvention relates to an improvement in an analytical method andapparatus wherein very small amounts of certain components of mixturesmay be accurately detected and measured.

In copending application, Ser. No. 479,109, now US. Pat. No. 3,560,158filed Aug. 12, 1965, there is described a technique for the detectionand measurement of quantities of materials well beyond the lower limitsof present chromatographic methods. In the method described in theaboveidentified application, a sample containing a compound having alabile-hydrogen atom is passed via a carrier gas as a driving forcethrough a column packed with a material which contains labile-tritiumatoms. As the sample passes through the column, the labile-hydrogenatoms in the sample exchange with the labile-tritium atoms in the packedcolumn such that on exiting from the column, thelabile-hydrogen-containing compound initially present in the sample hasbeen converted to a labile-tritium-containing compound, and thus isradioactive. The effluent from the packed column containing thelabile-tritium compound(s) is sent to a suitable radioactive detectorwhich detects the radiation from the tritium in the com pounds. Theamount of radiation detected is then related to the amount of thelabile-hydrogen-containing compound that was originally present in thesample mixture. In a sample mixture containing a plurality ofcomponents, the mixture is usually separated into its various individualcomponents by means of commonly known gas chromatographic columns. Theseparated components are then passed to the packed column containing thelabile-tritium substrate and any of the components which happen tocontain labile-hydrogen atoms then undergo exchange as described above.

The method described in the above-identified application is also usefulin the identification of components in samples, which although containno labile hydrogen themselves, are convertible to compounds containingsuch. In this instance, the component is first subjected to a suitableconversion means such as a combustion techniqueusing oxygen as theoxidant whereby the components are converted to compounds containinglabile-hydrogen atoms. The thus converted compound is thenpassed to thepacked column containing the labile-tritium substrate as explainedabove. As above, the sample mixture can first be separated intoindividual components by suitable chromatographic techniques. Althoughthe abovedescribed methods provide extremely valuable and accuratetechniques for the detection and measurement of extremely small amountsof components, they present, by virtue of the fact that they utilizeradioactive materials, certain potential safety hazards. Since usuallythe amount of the labilehydrogen-containing compound or compoundconvertible thereto whose detection and measurement is sought, ispresent in extremely small amounts in the sample mixture, the amount oflabiletritium-containing compound leaving the analytical system isnegligible in terms of presenting a radiation hazard to health. However,should the operator of the system accidentally inject a samplecontaining extremely large quantities of a labile-hydrogen-containingcompound or compound convertible thereto, the effluent from the detectorreleased to atmosphere would contain an amount of tritium-containingcompound which could potentially pose a hazard to health.

SUMMARY OF THE INVENTION It istherefore an object of the presentinvention to provide an improved analytical method.

Another object of the present invention is to provide an improvement inan analytical method employing radioactive substances which renders thetechnique free from safety hazards caused by operator error.

Still another object of the present invention is to provide animprovement in a system used for the detection and measurement ofextremely small amounts of materials and employing radioactive materialswhich renders the system substantially free from radiation hazards dueto operator error.

Additional objects will become apparent from the description givenherein, the attached drawings and the appended claims.

The improvement in the above-described methods which overcomes theproblem of possible operator error and which is provided by thisinvention comprises contacting the eftluent from the detection systemwith a substance having labilehydrogen atoms, the substance beingpresent in such an amount that substantially all of the tritium presentin the compound exchanges with the hydrogen present in the substance.The improvement described above is applicable to cases in which thesample being measured contains a labile-hydrogencontaining compound orto cases where the sample contains no labile-hydrogen-containingcompound but does contain compounds which are convertible thereto.

The present invention also provides an improvement in an analyticalsystem for carrying out the above-described method which comprises asuitable housing containing a substance having labile-hydrogen atoms,said housing having an inlet and an outlet, the inlet of said housingbeing connected to the outlet of said detection means whereby theeffluent from the detection means passes through the housing.

BRIEF DESCRIPI ION OF THE DRAWINGS FIGS. 1, 2 and 3 represent schematicflow diagrams of different embodiments of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, asample mixture containing at least one compound having a labile-hydrogenatom is passed either in the liquid or gaseous phase, though preferablyin the gaseous phase, by means of line 10 into exchange column 11 whichis packed with a fixed phase 12, hereinafter referred to as a substrate.This substrate 12 is one containing exchangeable tritium. As the samplemixture passes through column l1 and over substrate 12, the compounds inthe mixture which contain labile hydrogen exchange their labile hydrogenfor the tritium of substrate 12 until an exchange equilibrium isreached. The mixture now containing tritium-containing compounds passesfrom column 11 by means of line 13 and through radioactivity detector 14by means of which the radioactivity of the tritium in the mixture ismeasured. The type of radioactivity detectors useful in the presentinvention are hereinafter discussed. By measuring the radioactivity ofthe mixture, the amount of tritium, which has a known amount ofradioactivity per unit of weight, can be determined. By determining theamount of tritium passing from column 11, the concentration of thetritium-containing compounds, which initially were the compoundscontaining labile hydrogen, can be obtained. In practical usage, theradioactivity response of detector 14 will most often be transmitted toa recorder 15 where it is continuously recorded in a desired form. Thetritium-containing components pass from radioactivity detector 14 bymeans of line 16 into column 17 which is a tritium trap, containing asubstance 18 which has labile-hydrogen atoms. Upon passing throughcolumn 17, the labile tritium present in the effluent emerging fromdetector 14 exchanges with the labile hydrogens present in the substancein column 17 such that the efiluent emerging from column 17 containsnegligible quantities of tritium so far as posing a health hazard isconcerned. Should a sample containing a large concentration of alabile-hydrogen-containing compound be accidentally injected into thesystem through 10, it is seen that the presence of column 17 containingsubstance 18 will reduce the radioactivity of the effluent to a safelevel and thus the effluent ultimately vented via line 19 will beharmless. The embodiment of the analytical method depicted in FIG. 1 isparticularly useful wherein the analysis is either for the totalconcentration of labile-hydrogen-containing compounds in the mixture orfor the detection and determination of the amount of alabile-hydrogen-containing compound in a mixture when only one of suchcompounds is present. If two or more labile-hydrogen-containingcompounds are present in the mixture and it is desired to detect andmeasure the amounts of each of these separately, the analyticaltechnique described in relation to FIG. 2 is most often used.

With particular reference to FIG. 2, a mixture containing two or moredifierent compounds having labile-hydrogen atoms is resolved into itscomponents by introducing the mixture via line 20 into a separatingcolumn 21 in which means 22 are provided for separating the mixture intoits components. Each component having a labile-hydrogen atom then passesseparately from any other compound having labile-hydrogen atoms fromseparating column 21 by means of line into exchange column 11 whereinthe labile-hydrogen atoms are exchanged for tritium and theradioactivity of the resulting tritium-containing componentssubsequently detected and measured as described above in reference toFIG. 1. Column 17, of course, performs the same function as describedabove in the embodiment of FIG. 1, preventing release of dangerousquantities of a tritium-labiled material to atmosphere.

Again, referring to FIG. 2, the means 22 provided in separating column21 for resolving the mixture into its components include any meanswhereby the mixture may be separated into its components or at least thecompounds containing labile-hydrogen atoms may be separated one fromanother. Such separation methods as selective adsorption, selectiveabsorption or other combinations of these are usually favored, thoughother techniques such as fractionation, diffusion through permeablemembranes and the like may be used. The mixture may be separated in thevapor or liquid state/As a practical matter, the separation means mostoften takes the form of a conventional chromatographic column operatedaccording to conventional gas chromatographic techniques.

In FIG. 3, an analytical technique is presented which is particularlyuseful in the detection of compounds which do not containlabile-hydrogen atoms, but which may be converted by chemical orphysical means to compounds which do contain labile-hydrogen atoms. Inthis embodiment, the mixture is passed by means of line 23 into aconversion chamber 24. This conversion chamber may be of any type whichwill cause conversion of certain components of the mixture to compoundshaving labile-hydrogen atoms, either by chemical or physical conversionmeans. The resulting conversion products exit conversion chamber 24 andpass by means of line 10 into exchange column 11 and over substrate 12by means of which the labile-hydrogen atoms in the conversion productsare exchanged for tritium and detected and measured as described abovein reference to FIG. 1. As in the case of the techniques described withreference to FIGS. 1 and 2 above, column 17 serves the same function inthe technique described in FIG. 3. If two or more compounds convertibleto compounds having labile-hydrogen atoms are present in the mixture orif compounds having labile-hydrogen atoms and compounds convertible tocompounds having labile-hydrogen atoms are both present in the initialmixture, and detection and measurement of each of these compounds isdesired, it is usually necessary to first resolve the mixture into itscomponents as described in reference to FIG. 2 and then pass thecomponents through conversion chamber 24 individually.

The means by which compounds which do not contain labile-hydrogen atomsmay be converted to other compounds which do contain labile or activehydrogen atoms may be any of the conventional conversion processeseither chemical or physical, which will producelabile-hydrogen-containing compounds from these compounds. The simplestand most useful of these methods, particularly when the convertiblecompound is a hydrocarbon, hydrogen or oxygen, is combustion, whichproduces water as one of the combustion products. It is, of course,necessary for accurate determination that the combustion or conversionmethod be one which produces a quantitative conversion or at least aconversion of known and reproducible efliciency of the convertiblecompounds to compounds containing labile-hydrogen atoms.

The analytical method described above to which the improvement of thepresent invention applies is based upon .the exchangeability of labilehydrogen of compounds with tritium which is a radioactive-hydrogenisotope of mass number 3. When a labile-tritium-containing substratecomes in contact with compounds containing labile-hydrogen atoms, thereis a rapid exchange of the labile-hydrogen atoms with tritium atomsuntil an exchange equilibrium is reached. The radioactivity of thetritium is readily measurable while that of the labile hydrogen is not.The beta radiation of the tritium compounds may be measured byconventional means for measur ing radioactivity, such as Geigercounters, proportional counters, scintillation counters, ion collectionchambers, and the like. Preferably, for greater sensitivity, theradioactivity of the tritium compounds is measured by means ofscintillation counters or ion collection chambers, usually the lattermeans being preferred over the former.

As can be seen from above, the improvement set forth by the presentinvention renders the analytical method to which it is applied safe andalmost totally free from operator error. As explained, in most cases thesample mixtures being analyzed will contain very minute amounts oflabile-hydrogencontaining compound. In fact, the analytical methodtowhich the improvement of the present invention applies is primarilyaimed at the analysis of trace quantities of labile-hydrogencontainingimpurities in various sample mixtures. However, should a sample beinjected into the system which contains large quantities, i.e., 75 partsper million, of a compound having labile-hydrogen atoms, the method andapparatus of the present invention will prevent the release to theatmosphere of a large quantity of tritium-containing material.

The contacting of the effluent from the detection means called for bythe present invention can be carried out in several different ways. Onemethod of contacting is simply to vent the effluent from the detectionmeans into a container containing the substance having labile-hydrogenatoms. A more preferred method of contacting is to prepare a column,preferably out of a suitable tubular member, which has a bed of thesubstance containing labile-hydrogen atoms, connect one end of thecolumn to the outlet of the detection means and allow the effluent fromthe detection means to percolate through the column. This latter methodof contacting insures maximum contact and therefore maximum exchange ofthe labile tritium in the compound with the labile hydrogen in thesubstance.

Practically any substance which contains any labile or exchangeablehydrogen atoms can be employed in the tritiurn trap. It is preferredhowever, that the substance chosen for use in the tritium trap containgreater than 0.1 percent by weight of labile-hydrogen atoms. Obviouslythe greater the concentration of labile-hydrogen atoms in the substance,the less substance must be used in the tritium trap.

The substance containing the labile-hydrogen atoms can be either aliquid or a solid. One disadvantage in using a liquid, is that theeffluent from the detecting means must generally be scrubbed through theliquid. This can result in excessive back pressure to the carrier gasflow and cause tailing or other undesirable effects on the analyticalmethod. Nonetheless, if desired, a liquid may be employed as thesubstance in the tritium trap. Obviously, any number of liquids qualifyfor use. Suitable examples include alcohols, acids, amines, water, andany other of the well known labile-hydrogen-containing liquids.

For all around ease of operation, and convenience, itis preferable thatthe substance containing the labile-hydrogen atoms be a solid andespecially a particulate or fibrous solid. The use of such solids makesit relatively easy to prepare a packed column which ofi'ers minimumresistance to carrier gas flow and thus minimizes any back pressureeffects. The term particulated as used herein, refers to solid pieceshaving an averagesize ranging from 300 mesh up to chunks having anaverage diameter of one-half inch. The shape of the solid particles isnot critical. When a solid is employed as the substance in the tritiumtrap, it can be any one of numerous solid substances containing hydroxylgroups, amine groups, amide groups, or the like. Examples includealumina, silica, silica gel, clays such as kaolin, diatomaceous earth,molecular sieves, hydrated salts such as hydrated calcium sulfate,hydrated calcium chloride, polymeric aromatic amines, polymeric aromaticamides, and numerous other solid materials having like characteristics.In general, any solid material containing labile-hydrogen atoms is asuitable substance for use in the tritium trap of the present invention.

Preferably, the amount of the substance in the tritium trap should betimes or greater the amount by weight of the labile-tritium-containingcompound in the effluent from the detector. Smaller amounts can beemployed if desired, however, with no sacrifice of safety.

The operating conditions employed in applying the present invention mayvary over a relatively wide range. Preferably the temperature of thetritium trap is maintained at or near ambient to minimize thepossibility of stripping ofi labilehydrogen atoms as water, etc.However, higher temperatures can be employed if desired, the kinetics ofthe exchange being favored by higher temperatures. Pressures may rangefrom sub-atmospheric to as high as 100 psig., and higher. The residencetime of the effluent in the column containing the substance havinglabile-hydrogen atoms, i.e., the trap, may be very short withoutreducing the safety factor. For example, residence times of as low as0.01 seconds will be sufficient to achieve greater than 99 percentexchange of the tritiumfor the labile hydrogen.

The use of the present invention will prevent the immediate escape ofharmful quantities of tritium to atmosphere. Once it has been determinedthat an excessive amount of a labilehydrogen-containing compound waspresent in the initial sample mixture, and that the tritium trap nowcontains a potentially hazardous amount of tritium, the tritium trap isremoved and the tritium therein disposed of in a suitable manner. Thisprocedure is necessitated by the fact that, although the tritium isinitially trapped, it will eventually elute off of the column followingwell known principles of gas chromatography. This, however, presents noproblem inasmuch as the operator will have been apprised of the factthat an excessive amount of labile-hydrogen-containing compound hasbeen'injected into the system initially because of the excessiverecorder response due to the peak from the tritium-containing compound.

In the analytical method to which the present invention applies, thesource of the tritium is generally a tritium-containing fixed phase orsubstrate with which the labile-hydrogen-containingcompounds in thesample mixture are contacted. This tritium-containing substrate can beprepared by several well known methods. Generally the substrate materialused for preparing the tritium-containing substrate are those having assubstituents hydroxyl, amine, amide, or any other like group havinglabile-hydrogen atoms attached thereto. Suitable substrates includepolymeric aromatic amines, polymeric aromatic amides, benzimidazolepolymers and polybenzothiazoles.

The materials which may be detected and measured by the analyticalmethod in which the present invention applies can be divided into twomain classes; (1) those which contain compounds having labile-hydrogenatoms such as water, alcohols, amines, amides, acids and the like; and(2) those having compounds with no labile hydrogen but which may, bysuitable conversion means, be converted to compounds having labilehydrogen. This latter class of compounds or elements includeshydrocarbons, oxygen, hydrogen, the halogens, carbon dioxide and manyother compounds. In particular, hydrocarbons, oxygen and hydrogen areespecially amenable to conversion to labile-hydrogen-containingcompounds. For example, hydrocarbons may be quantitatively converted towater and CO by combustion techniques and the water obtained by thecombustion may then be detected and measured by the analyticaltechnique.

Ill

The analytical technique to which the present invention applies iscarried out with the mixture in a fluid state, and more preferably theentire operation is carried out in the gaseous state. In carrying outthe technique in the gaseous state, the carrier gas used to sweep thesample mixture through the system can be any carrier gas normallyemployed in gas chromatography with the exception that the gas shouldnot be one containing any labile-hydrogen atoms.

To illustrate the effectiveness of the present invention, the followingexample is presented.

EXAMPLE a 10 millimeter glass tube, three inches long, was filled with10 grams of molecular sieve, type 13A. The thus prepared tritium trap"was connected between the tritium exchange column and the detector. Inother words, rather than the tube containing the molecular sieve whichcorresponds to column 17 of FIG. 1 being connected to the effluent fromdetector 14, column 17 was placed between column 12 and detector 14. Asample containing suflicient labile hydrogen to displace l microcurie oftritium from the exchange column was injected into the system throughline 10. No tritium-containing materials emerged for a period of over 1hour. This was evidenced by the fact that recorder 15 maintained avirtually constant base line for well over the l-hour period.

As can readily be seen from the foregoing example, the present inventionprovides a method and means of preventing possible accidental release oftritium-containing materials into the atmosphere.

What is claimed is:

1. In an analytical method for the detection and measurement oflabile-hydrogen-containing compounds wherein a sample mixture containingat least one compound having labile hydrogen is passed through a fixedphase of a labile-tritium-containing substrate such that the labilehydrogen in said compound exchanges with the labile tritium in saidsubstrate and the resulting labile-tritium-containing compound isdetected by suitable radioactivity detecting means, the improvementwherein excessive amounts of said labile-tritium-containing compound inthe efiluent from said detecting means are prevented from release toatmosphere comprising contacting said efi'luent with a substance havinglabile-hydrogen atoms, said substance being present in an amountsufficient to effect substantially complete exchange of the labiletritium in said tritium-containing compound with the hydrogen in saidlabile-hydrogen-containing substance.

2. The method of claim 1 wherein said contacting is carried out bypassing said effluent through a column containing a bed of saidsubstance.

3. The method of claim 1 wherein the amount of said substance is 10times the amount by weight of said labile-tritiumcontaining compound insaid efiluent.

4. The method of claim 1 wherein said substance is a fibrous solid.

5. The method of claim 1 wherein said substance is a particulate solid.

6. The method of claim 1 wherein said substance contains greater than0.1 percent by weight of labile-hydrogen atoms.

7. The method of claim 1 wherein said substance contains greater than0.1 percent by weight of labile-hydrogen atoms.

8. In an analytical method for the detection and measurement ofcomponents convertible to labile-hydrogen-containing compounds wherein asample mixture containing at least one component convertible to alabile-hydrogen-containing compound is subjected to a suitableconversion means, the

resulting labile-hydrogen-containing compound is passed through a fixedphase of a labile-tritium-containing substrate such that the labilehydrogen in said labile-hydrogen-containing compound exchanges with thelabile tritium of said substrate, and the resultinglabile-tritium-containing compound is detected by suitable radioactivitydetection means, the improvement wherein excessive amounts of saidlabile-tritiumcontaining compound in the effluent from said detectingmeans are prevented from release to atmosphere comprising contactingsaid efiluent' with a substance having labilehydrogen atoms, saidsubstance being present in an amount sufficient to effect substantiallycomplete exchange of the labile tritium in said tritium-containingcompound with the hydrogen in said labile-hydrogen-containing substance.

9. The method of claim 8 wherein said component convertible to saidlabile-hydrogen-containing compound is one selected from the groupconsisting of hydrocarbons, hydrogen and oxygen.

10. The method of claim 8 wherein said contacting is carried out bypassing said efiluent through a column containing a bed of saidsubstance.

11. The method of claim 8 wherein the amount of said substance is 10times the amount by weight of said labile-tritiumcontaining compound insaid effluent.

12. The method of claim 8 wherein said substance is a fibrous solid.

13. The method of claim 8 wherein said substance is a particulate solid.

14. ln a system for the analysis of samples containing compounds havinglabile-hydrogen atoms or components convertible thereto, comprising: anexchange column packed with a substrate containing labile-tritium atoms;means to introduce a sample into said system upstream from said exchangecolumn; means to introduce a fluid carrier stream into said system, saidcarrier stream serving to transport said sample through said exchangecolumn; means for withdrawing the sample and carrier fluid from saidexchange column; and means for detecting and measuring the radioactivityof the resulting tritium-containing compounds, the combination of ahousing having an inlet and an outlet, said housing containing asubstance having labile-hydrogen atoms, and means connecting the inletof said housing with the outlet of said detecting means vwhereby theeffluent from said detecting means flows through said housing.

15. The combination of claim 14 having means connected between wheresaid sample is introduced into said system and

2. The method of claim 1 wherein said contacting is carried out bypassing said effluent through a column containing a bed of saidsubstance.
 3. The method of claim 1 wherein the amount of said substanceis 10 times the amount by weight of said labile-tritium-containingcompound in said effluent.
 4. The method of claim 1 wherein saidsubstance is a fibrous solid.
 5. The method of claim 1 wherein saidsubstance is a particulate solid.
 6. The method of claim 1 wherein saidsubstance contains greater than 0.1 percent by weight of labile-hydrogenatoms.
 7. The method of claim 1 wherein said substance contains greaterthan 0.1 percent by weight of labile-hydrogen atoms.
 8. In an analyticalmethod for the detection and measurement of components convertible tolabile-hydrogen-containing compounds wherein a sample mixture containingat least one component convertible to a labile-hydrogen-containingcompound is subjected to a suitable conversion means, the resultinglabile-hydrogen-containing compound is passed through a fixed phase of alabile-tritium-containing substrate such that the labile hydrogen insaid labile-hydrogen-containing compound exchanges with the labiletritium of said substrate, and the resulting labile-tritium-containingcompound is detected by suitable radioactivity detection means, theimprovement wherein excessive amounts of said labile-tritium-containingcompound in the effluent from said detecting means are prevented fromrelease to atmosphere comprising contacting said effluent with asubstance having labile-hydrogen atoms, said substance being present inan amount sufficient to effect substantially complete exchange of thelabile tritium in said tritium-containing compound with the hydrogen insaid labile-hydrogen-containing substance.
 9. The method of claim 8wherein said component convertible to said labile-hydrogen-containingcompound is one selected from the group consisting of hydrocarbons,hydrogen and oxygen.
 10. The method of claim 8 wherein said contactingis carried out by passing said effluent through a column containing abed of said substance.
 11. The method of claim 8 wherein the amount ofsaid substance is 10 times the amount by weight of saidlabile-tritium-containing compound in said effluent.
 12. The method ofclaim 8 wherein said substance is a fibrous solid.
 13. The method ofclaim 8 wherein said substance is a particulate solid.
 14. In a systemfor the analysis of samples containing compounds having labile-hydrogenatoms or components convertible thereto, comprising: an exchange columnpacked with a substrate containing labile-tritium atoms; means tointroduce a sample into said system upstream from said exchange column;means to introduce a fluid carrier stream into said system, said carrierstream serving to transport said sample through said exchange coluMn;means for withdrawing the sample and carrier fluid from said exchangecolumn; and means for detecting and measuring the radioactivity of theresulting tritium-containing compounds, the combination of a housinghaving an inlet and an outlet, said housing containing a substancehaving labile-hydrogen atoms, and means connecting the inlet of saidhousing with the outlet of said detecting means whereby the effluentfrom said detecting means flows through said housing.
 15. Thecombination of claim 14 having means connected between where said sampleis introduced into said system and said exchange column said means beingfor converting components present in said sample into compounds havinglabile-hydrogen atoms.
 16. The combination of claim 15 wherein theconversion means comprises a combustion apparatus.
 17. The combinationof claim 14 wherein said housing comprises a tubular member.
 18. Thecombination of claim 17 wherein said substance contains greater than 0.1percent by weight labile-hydrogen atoms.
 19. The combination of claim 18wherein said substance is a particulate solid.